1. Technical Field
The present invention relates generally to a shutter assembly. In particular, the invention relates to a system and method for providing power to a motorized shutter assembly.
2. Background of the Invention
Shutter assemblies are frequently employed to cover an aperture in a wall, such as for example, a window or an entryway, and to provide security and/or protection from weather, intruders, and the like. The shutter assembly typically includes a shutter curtain formed from a plurality of interlocking slats. When a user wishes to expose the wall aperture, the shutter curtain is raised by winding the interlocking slats about a rotatable drive tube. When a user wishes to cover the wall aperture, the shutter curtain is lowered by rotating the drive shaft to unroll the interlocking slats.
A number of mechanisms are available for winding and unwinding the shutter curtain. One known type of manual shutter assembly includes a gearing system to raise and lower the shutter curtain. The gearing system typically includes a driving gear, such as for example a worm gear, and a driven gear, such as for example a spur gear. The driven gear is typically coupled to the drive tube such that rotation of the driven gear results in a linear rotation of the drive tube. The driving gear is adapted to receive a first shaft of a universal joint while a second shaft of the universal joint is adapted to be couple to a crank pole. The gear assembly typically includes an indexing mechanism to provide a positive stop when the shutter curtain is in a fully lowered position so that the operator does not inadvertently roll the shutter curtain back up again. In operation, the crank pole is used to rotate the universal joint thereby rotating the driving gear. The rotating driving gear rotates the driven gear which in turn rotates the drive tube thereby raising or lowering the shutter curtain.
During the raising and lowering operations of the shutter curtain using the above described manual shutter operator, the articulated joints of the universal joint may be subjected to significant pressure making them more prone to failure. The more acute the angle of operation of the crank pole, the greater the stress experienced at the joints. Also, often times there is a large gear ratio between the driving gear and the driven gear requiring the operator to rotate the crank pole numerous times to fully raise or lower the shutter curtain. For example, a gear assembly with an eleven-to-one gear ratio requires the operator to rotate the crank pole eleven times in order to turn the drive tube once. It can often be tiring and/or time consuming for a user to raise or lower the shutter curtain on such a shutter assembly, especially when the user is raising or lowering several such shutter curtains. Furthermore, a user may not be able sense the difference between the indexing mechanism's positive stop and the torque required to raise the shutter curtain. As a result, the shutter curtain may be inadvertently back-rolled by the user, which may cause damage to the shutter curtain and/or its associated hardware.
Another known type of shutter curtain implements a motor assembly unit to rotate the crank pole, which in turn rotates the universal joint. The rotation of the universal joint causes a rotation of the driving gear which in turn rotates the driven gear. The rotating driven gear rotates the drive tube to lower and/or raise the shutter curtain. Such a motor assembly unit can be heavy and cumbersome because it typically houses both a motor and a battery to power the motor. A user has to support and balance the weight of the unit, and also act as a counterbalance to the torque produced by the motor to drive the crank pole to raise and/or lower the shutter curtain. The use of such a motor assembly unit may also increase the likelihood of universal joint failure.
Yet another known type of shutter curtain assembly implements a tubular motor assembly to essentially directly rotate the drive tube. The tubular motor assembly is typically affixed to the shutter curtain end cap or bracket assembly. The tubular motor is typically inserted into the drive tube of the shutter assembly, and may include a plurality of reduction gears and a counting mechanism to track the appropriate number of rotations necessary to stop the shutter curtain in at the desired position. A further known type of shutter curtain assembly incorporates a motor assembly into an end cap of the shutter curtain assembly. In each of these motorized shutter curtain assemblies, some form of power is required to drive the motor. It would be desirable to provide a motorized shutter assembly that does not require a permanent electrical connection to provide power to the motor.